• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.93-96
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• 2000

A diffusion-influenced pseudo-first order reversible reaction A + B ⇔C + B is investigated by the molecular dynamics (MD) simulation method. Theoretical finding that the temporal evolution of reactants [conditional probabilities] in the reversible system can be expressed by the irreversible survival probability with an effective rate parameter is confirmed even in the presence of solvent particles. We carry out molecular dynamics simulations for both the irreversible and the reversible cases to evaluate the survival and the conditional probabilities for each cases. When the resultant irreversible survival probability is inserted into the proposed relation, the conditional probabilities given by the simulation are exactly reproduced.

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.57-63
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• 1994

Digital simulation program for one-dimensional geometric systems of electrochemical phenomena was developed. The accuracy of the digital simulation is discussed by comparing with the known solutions. Applying this program to the linear sweep voltammetry at a planar electrode for the electrode reaction, 0 + ne${\to}$R, the accurate current functions for the reversible and totally irreversible charge transfer systems were obtained. Comparing these current functions with the simulated voltammograms for various other values of ${\alpha}$ (0.1 to 1.0) and ${\Lambda}\;(10^{-5}\;to\;10^5)$, the revised zones that are different from those proposed by Matsuda and Ayabe for the reversible and totally irreversible systems are proposed. For ${\alpha}{\ge}$0.1 the reversible zone is in ${\Lambda}{\ge}10^{1.7}$ and the totally irreversible zone is in ${\Lambda}{\le}10^{-1.7}$, where ${\Lambda}=k^{\circ}/ [D_o^{1-{\alpha}}D_R^{\alpha}(nF/RT)v]^{1/2}$.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.11
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• pp.1233-1240
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• 2014

For the last three decades after the advent of the Toffoli gate in 1980, while many reversible circuit syntheses have been presented reversible embedding methods onto suitable reversible functions, only a few proposed direct irreversible-to-reversible mapping methods without reversible embedding. In this paper we present two effective policies to reduce the gate cost and complexity for the existing direct reversible mapping methods without reversible embedding. In order to develop new cost reduction policies we consider the cost influence of Toffoli module according to NOT gate arrangement in classical circuits. From this we deduced an inverse proportional property between inverting input numbers of classical AND/OR gates and reversible Toffoli module cost based on a fact - the inverting inputs of classical AND(OR) gates increase(decrease) the Toffoli module cost. We confirm the applications of the inverting input rearrangement and maximum fan-out policies preceding direct reversible mapping will be effective method to improve the reversible Toffoli module cost and complexity with the parallel using of the fan-out and supercell ones.

• The Journal of the Korean dental association
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• v.50 no.5
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• pp.244-255
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• 2012

Temporomandibular disorder(TMD) is described as a cluster of disorders characterized by pain in the preauricular area and/or the muscles of mastication; limitations or deviations in mandibular range of motion; and noises in the TMJ during mandibular function. The most common symptom in TMD patients is pain that is aggravated by chewing or other jaw function. These symptoms are appeared when the stimuli loaded in TMJ are over the physiologic tolerance. The primary goal in treatment of TMD is to alleviate pain and lor mandibular dysfunction. TMD treatment can be divided into 2 categories: reversible and irreversible methods. Reversible methods include medication, thermal therapy, habit modification, physical therapy, appliance therpy and arthrocentesis and lavage and irreversible methods include arthroscopic lysis, surgery, occlusal adjustment et al. It is widely accepted that reversible methods are ther first choice of treatments. However if reversible ones are not effective, irreversible methods are considered.

• Nano
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• v.13 no.10
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• pp.1850120.1-1850120.9
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• 2018

Two-dimensional poly(dimethylsiloxane) (PDMS) films with wavy patterns were studied in order to investigate reversible and irreversible wetting effects. Pre-strained, surface oxidized layers of PDMS were used to form relieved wavy geometries, on which hydrophobic functionalization was carried out in order to produce irreversible wetting effects. Wavy-patterned PDMS films showed time-dependent reversible wetting effects. The degree of surface wettability could be tuned by the choice of wavy groove geometries. And the groove geometries were controlled via $O_2$ plasma treatment and mechanical pre-straining. The pre-strained, buckled PDMS films were applied to the fabrication of hydrophobic polystyrene nano-patterns using colloidal self-assembly, where the colloids were arrayed in two-dimensional way. The wavy polystyrene films were found to be more hydrophobic relative to flat polystyrene films. The grooving methodology used in this study could be applied to enhancing the hydrophobicity of other types of polymeric thin films, eliminating the need for chemical treatment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.7
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• pp.387-393
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• 2016

Threshold voltage shift has been observed from many thin-film transistors (TFTs) and the time evolution of the shift can be modeled as the stretched-exponential and -hyperbola function. These analytic models are derived from the kinetic equation for defect-creation or charge-trapping and the equation consists of only reversible reactions. In reality TFT's a shift is permanent due to an irreversible reaction and, as a result, it is reasonable to consider that both reversible and irreversible reactions exist in a TFT. In this paper the case when both reactions exist in parallel and make a combined threshold voltage shift is modeled and simulated. The results show that a combined threshold voltage shift observed from a TFT may agrees with the analytic models and, thus, the analytic models don't guarantee whether the cause of the shift is defection-creation or charge-trapping.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.416-426
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• 1991

The effects of an irreversible or a reversible $\alpha_1$-adrenoceptor antagonist (dibenamine or prazosin) on $\alpha_1$-adrenoceptor-mediated vasoconstrictions were studied in the endothelium-denuded rat aorta. In these experiments, the mobilization of intracelluier calcium and translocation of extracellular calcium were also studied. To exclude the modulation of endothelium releasing EDRF and EDCF, the endothelium was removed in all rat aortas. Contraction induced by phenylephrine (a full $\alpha_1$-adrenoceptor agonist) was separated into a fast phasic component of the response due to the release of intracellular calcium and a slow tonic one due to the influx of extracellular calcium. Pretreatments with increasing doses of reversible $\alpha_1$-adrenoceptor antagonist prazosin, as well as irreversible $\alpha_1$-adrenoceptor antagonist dibenamine, inhibited the phasic component of phenylephrine-induced contraction more effectively than the tonic one. Pretreatment of dibenamine (0.2 $\mu{M}$) or prazosin (10 nM) to the rat aorta abolished phasic response but remained tonic one about 41% and 51%, respectively. These results suggest that as the efficiency of phenylephrine was progressively reduced by pretreatments with increasing doses of an irreversible or a reversible $\alpha_1$-adrenoceptor antagonist (dibenamine or prazosin), the contraction induced by phenylephrine became progressively more dependent on the influx of extracellular calcium.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.853-860
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• 2000

Objective : The purpose of our experimental study was to analysis the advantages and disadvantages in the reversible and irreversible cerebral ischemic models with rats by staining with Neutral Red(NR) solusion, 2% 2,3,5-triphenyltetrazolium chloride(TTC) and Hematoxylin & Eosin(H & E). Methods : We have measured the range of cerebral infarction in the rat to get a suitable ischemic model along the object of study with and without craniectomy. With craniectomy, 9 rats were sacrificed for irreversible cerebral ischemic model by means of ligation at proximal(group I) and distal(group II), and coagulation at proximal(group III) middle cerebral artery. Also, 6 rats were sacrificed for irreversible(group IV) and reversible(group V) cerebral ischemic model using nylon thread without craniectomy. The sizes of infarction were measured by staining the coronal sections of the brain with NR solusion, TTC and H & E. Results : There are no difference of physiological parameters comparing the each group. Cerebral infarction was not observed in group II, but it's volume was largest in group IV. Disadvantages of craniectomy group(I, II, III) are the long duration of operation and cortical damage by procedure. It's advantage is confirmation of the middle cerebral artery occlusion and cessation of blood flow through the operative microscope. In case of ischemic models using nylon thread (group IV, V), it is hard to identify the interruption or recirculation of blood flow through the middle cerebral artery, but the advantage is the simplicity of operative technique which reduces the operation time and minimizes the cerebral damage due to craniectomy. Therefore, it seems important to set up the reversible and irreversible ischemic models by carefully considering advantages and disadvantages listed above. Conclusion : TTC staining seems to be effective since it reflects the histological damage sufficiently and quickly. It is hoped that researches focused on ischemic penumbra, which became popular recently, will be further carried on with use of NR staining, optical microscope and electron microscope.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.280-285
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• 1993

The bioactivity of garlic extract was evaluated, based on the inhibition of soybean lipoxygenase. While the inhibition of lipoxygenase by the chloroform extract (1$_{50}$ value after 10min precirculation, 55mg/$m\ell$) of garlic homogenate shows the property as irreversible inhibitors, the aqueous extract (1$_{50}$ value, 65mg/$m\ell$) appeared to contain mainly reversible inhibitors. In the related study, diallyldislufide and dimethyldisulfide inhibited the enzyme with 1$_{50}$ value of 1.3mM and 18mM, respectively. These disulfides demonstrated both irreversible and reversible patterns of inhibition. In addition, synthetic alliin(allylcysteine sulfoxide) was found to inhibit the enzyme at high concentration (approximately 22%, at 10mM), and its decomposition products showed the irreversible property in the inhibition, in contrast to S-ethyl cysteine sulfoxide which expressed no significant inhibition. Thus, it is suggested that the garlic macerate contains both irreversible and reversible sulfur inhibitors.itors.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3287-3296
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• 1994

For the numerical computation of three-dimensional compressible flow field within a blade row in a centrifugal compressor, a quasi 3-dimensional solver which combines a reversible B-B flow and an irreversible H-S flow using finite element methods was developed. In a reversible B-B flow, the governing coordinates are modified in order to be applied to any type of turbomachinery, and two kinds of stream functions are introduced in order to make the Kutta condition exactly satisfied. In an irreversible H-S flow, the changes of entropy in the irreversible governing equations are determined not by empirical source but by the theoretical treatment of dissipation forces. The dissipation forces are obtained from the distribution of shear stresses in the flow passage which are given from the wall shear stresses using the exponential functions. A more accurate quasi-3-dimensional solver is established where the effect of body forces is involved in the non-axisymmetric H-S flow. Some numerical results obtained from authors' previous studies for axial flow machines assure that the present method is able to predict well as long as the flow is subsonic and not under strong viscous effect.